The present invention relates to a braking and driving mechanism for a nail gun, and particularly to a pressing rod pivotably disposed in a magazine of a nail gun. The pressing rod can automatically detect the number of remaining nails in the magazine and brakes or releases a driving rod accordingly.
Generally, a braking mechanism is used in a nail gun to automatically detect whether there are adequate nails in a magazine and brake the shooting action of nail guns if there is no nail in the magazine. Usually, the braking mechanism disables a trigger valve of the nail gun thereby reminding of the user to reload nails. Currently, fine nails, for example, a kind of nail commonly called pin nail which has a thickness of about 0.6 millimeters to about 1.2 millimeters, is popularly used in nail guns.
For example, Taiwan issued patent No. 321044 discloses such a braking mechanism for a nail gun, in which a sliding member is employed to push nails into a nail driving groove. A braking member extends from an end side of the sliding member, and is capable of moving in a direction of the nail driving groove together with the sliding member at a displacement of the thickness of a nail after a nail is shot out of the nail gun. Finally, the braking member reaches to a move path of a driving rod of the nail gun to block the driving rod to move. As such, the shooting action of the nail gun is braked, and the user is reminded to reload nails. However, the braking member can merely move at a distance equals to the thickness of the last nail (e.g. about 0.6 millimeters) after the last nail is shot out of the nail gun. In other words, the braking member blocks the driving rod using an area having a width that is equal to the thickness of the last nail (e.g. about 0.6 millimeters). In such conditions, if the operator forcedly presses the driving rod, the driving rod may slide off the braking member. As a result, the braking mechanism fails to brakes the shooting action.
In addition, a technologically advanced braking mechanism is also disclosed in Taiwan issued patent No. M269156. The braking mechanism includes a touch member disposed on a nail driving member of a nail gun. An open end groove is defined in an end side of a magazine of the nail gun. A braking member that is capable of being triggered by the touch member to swing is pivotably disposed in the end groove. The touch member moves towards a direction of the a nail driving groove together with the nail driving member at a distance of the thickness of one nail for each nail shooting action, and finally the touch member pushes the braking member to obliquely swing out of the magazine to a move path of the driving rod. As such, the driving rod is blocked by the braking member, the shooting action of the nail gun is braked, and the operator is reminded to reload nails. However, when braking member is obliquely swung out of the magazine the driving rod is sustained by a slope surface of the braking member that is swung out of the magazine. In such condition, a component force of the force that the driving rod applies to the braking member along an inverse direction of a swing direction of the braking member may force the braking member to swing back to its original position but not stay at the braking position. As described above, the stability of above described braking mechanism is low, and may affect a success rate of the braking action of the braking mechanism. Therefore, there is a desire to overcome aforementioned problems.